1. Field of the Invention
The present invention generally relates to an adjusting mechanism, and more particularly, to an adjusting mechanism capable of adjusting the horizontal position and the vertical position of a light integration rod module (LIR module) from the same side of an optical engine.
2. Description of Related Art
Along with the modern video technology progress, optical projection apparatuses have been broadly used in various circumstances, such as home theater, small conference and addressing, or seminar. An optical projection apparatus includes an optical engine and a projection lens, wherein the optical engine is for providing an image beam and the projection lens is for projecting the image beam onto a screen. In addition, the optical engine usually includes a light source, an LIR module and a light valve. The light source is for producing a light beam, the LIR module is for homogenizing the light beam, and the light valve is for converting the light beam into the image beam.
In general speaking, the extent of homogenizing a light beam depends on the position where the light beam passes through the LIR of the LIR module. Accordingly, the LIR module usually has an adjusting unit for adjusting the position where the light beam is incident into a condenser lens after the light beam passes through the LIR, so that the light beam is preferably homogenized after departing from the LIR.
FIGS. 1A, 1B and 1C are diagrams respectively showing a top view, a bottom view and a sectional drawing of a conventional adjusting mechanism of the LIR module. Referring to FIGS. 1A, 1B and 1C, an optical engine 100 has an engine base 110 and a rod holder flat spring 120 fixed on the engine base 110. The engine base 110 has a first side wall 112 and a second side wall 114 adjacent to the first side wall 112. The rod holder flat spring 120 has a third side wall 122 and a fourth side wall 124 adjacent to the third side wall 122. The first side wall 112, the second side wall 114, the third side wall 122 and the fourth side wall 124 come together to form an accommodating space S for placing an LIR module 130 therein. In addition, a first spring portion 122a and a second spring portion 124a are respectively disposed on the third side wall 122 and the fourth side wall 124 to correspondingly provide an upward elastic force and a downward elastic force.
The LIR module 130 leans on a first spring portion 122a and a second spring portion 124a. The adjusting mechanism of the LIR module 130 includes a first adjusting screw 142 and a second adjusting screw 144 for respectively adjusting the positions of the LIR module 130 in a first axis (horizontal) and a second axis (vertical). The first adjusting screw 142 passes through the first side wall 112 of the engine base 110 to lean against the LIR module 130 so as to compress the second spring portion 124a to a desired extent by turning the first adjusting screw 142 and to furthermore adjust the relative position between the LIR module 130 and the rod holder flat spring 120 in the first axis. In the same way, the second adjusting screw 144 passes through the second side wall 114 of the engine base 110 to lean against the LIR module 130 so as to compress the first spring portion 122a to a desired extent by screwing the second adjusting screw 144 and to furthermore adjust the relative position between the LIR module 130 and the rod holder flat spring 120 in the second axis.
After the above-mentioned optical engine 100 has been assembled into a projector, a user is more convenient to turn the second adjusting screw 144 over the projector for further adjusting the vertical position of the LIR module 130. On the other hand however, the user does not easily manipulate a screw driver in the horizontal direction. Thus, the operator may need to take the whole projector apart so as to adjust the first adjusting screw 142 by turning and to furthermore adjust the horizontal position of the LIR module 130, which however would increase the difficulty of adjusting the position of the LIR module 130 and lengthen the operation time.